Developing low-cost and highly active bifunctional electrocatalysts for water splitting is very important but still remains a challenge. Herein, a novel bifunctional electrocatalyst composed of CoP and Ni2P nanoparticles implanted in a hollow porous N-doped carbon polyhedron (CoP/Ni2P@HPNCP) is synthesized by carbonization of Co/Ni-layered double hydroxide@zeolitic imidazolate framework-67 (Co/Ni-LDH@ZIF-67) followed by an oxidation and phosphorization strategy. The introduction of LDH can not only promote the formation of a hollow porous structure to supply more active sites, but also generate the CoP/Ni2P nanoheterostructure to afford extra active sites and modulate the electronic structure of the catalyst. As a result, CoP/Ni2P@HPNCP exhibits excellent pH universal hydrogen evolution reaction activity and alkaline oxygen evolution reaction activity. Furthermore, the electrolytic cell assembled from bifunctional CoP/Ni2P@HPNCP requires a cell voltage of 1.59 V in 1.0 M KOH at 10 mA cm-2, revealing its potential as a high performance bifunctional electrocatalyst.Surface-enhanced Raman spectroscopy (SERS) is mainly contributed by "hot spots". Due to the huge electromagnetic enhancement, "hot spots" have wide applications in surface analysis and surface catalysis. The in-depth research on the "hot spots" effect is conducive to understanding SERS enhancement mechanisms and designing substrates with high enhancement. At present, the investigation on the "hot spots" effect is mainly based on theoretical simulation and simple experimental models. https://www.selleckchem.com/products/pf-543.html However, little attention has been paid to the SERS substrates with practical applications. The main reason is that it is difficult to construct a suitable coupled model with great uniformity and sensitivity, which led to the lack of comparability of SERS intensities from different spots or substrates. In this work, Au nanoparticle mono-/bi-layer films coupled with Au single-crystal plate systems were constructed to investigate the distribution and transformation of "hot spots" dependent on the excitation wavelength by a single or dual probe-modified strategy, in which one or two types of molecules with distinct characteristic peaks were modified in different enhanced gaps. The results demonstrated that the wavelength that drove the transformation of the coupling mode from the "particle-particle" mode to the "particle-surface" mode was around 638 nm in the Au nanoparticle monolayer film (Au MLF) covered Au plate system. As the second naked Au MLF was transferred onto the first Au MLF, "hot spots" were transferred to the "particle-particle" gap between the upper and lower Au MLFs with a 638 nm laser as the excitation line. This work offers a novel avenue to investigate the "hot spots" effect in the complex multidimensional nanostructures, which is beneficial for the development of theoretical research and practical applications of SERS.As a typical group of coordination polymers, metal-organic zeolite (MOZs) frameworks inherit the topological and structural advantages of inorganic zeolites and display great application potential in many areas, including gas adsorption/separation, catalysis, luminescence and chemical sensing. In this review, we outline the recent progress in the synthesis, functionalization and application of metal-organic zeolite frameworks, mainly focusing on the basic structural design principle and synthesis strategy on 4-connect inorganic nodes and 2-connect organic linkers. Employing different valent metals, small inorganic TO42- units and high-nuclear clusters as 4-connect nodes, we derived multi-types of MOZs with a modified framework charge, improved stability and enhanced photo-/eletrocatalytic activity. Besides, the selection, functionalization and defect-engineering on the 2-connect ligands generated different topological and functional MOZs. Finally, the future trends and some perspectives in this area are outlined.Organic aerosols, complicated mixtures of organic compounds, are important constituents of atmospheric particulate matter. However, little is known about the size distributions and vertical profiles of these constituents at a molecular level in the urban boundary layer. Here, we characterized the molecular compositions of size-segregated samples collected simultaneously at two heights (8 m and 260 m above ground level) in urban Beijing during the winter of 2018. The CHO, CHNO, CHOS, and CHNOS subgroups in water-soluble organic carbon were characterized using a 15-T ultrahigh-resolution Fourier transform-ion cyclotron resonance (FT-ICR) mass spectrometer. We found that both their numbers and magnitudes increased with a decrease in the particle size, especially for high molecular weight (HMW) compounds, except CHNOS. The number of CHNOS species also increased in the coarse mode, presumably because the alkalinity could inhibit their hydrolysis in the coarse mode. The compounds in small particles with higher O/C ratios and carbon oxidation state were possibly more aged, while the coarse particles with more lipid- and peptide-like compounds should originate from fresh emissions. Moreover, as the oxidation state increases in small particles, functionalization is enhanced for sulfur-containing compounds with fracturing of the benzene ring, while CHO and CHNO are potentially dominated by demethylation with ring-retaining products. It is worth noting that common compounds with the same molecular characteristics accounted for more than 86% of the total compounds between 260 m and ground level (8 m), demonstrating that the aerosols were well mixed in the urban boundary layer. Nonetheless, the relative content of the compounds was higher at ground level due to the impact of primary emissions, which increased with the particle size. In addition, the compounds in submicron particles were more oxidized at 260 m, while the opposite was observed in the coarse mode.The ability to control adhesion is critical in various technologies including wearable electronics, pressure sensitive adhesives, and robotic systems. Biomimetic fibrillar structures, random surface roughness, and chemical surface treatments have been employed to modify the adhesion energy of materials used in these applications. However, polymer thin film dewetting has not been investigated as a surface modification tool to control adhesion. In this work, polystyrene thin films are thermally annealed on a polydimethylsiloxane substrate, causing them to dewet and form stiff, microscopic asperities on the soft substrate. The size of the asperities increases with increasing pre-annealing film thickness. Adhesion is quantified by flat-punch normal indentation testing. The largest asperities exhibited a decrease in adhesion to below the sensitivity of the instrument. More interestingly, the surfaces covered with the smallest asperities displayed a pressure-dependent adhesive response. By increasing the normal compressive stress applied prior to separation, the total debonding energy increased monotonically on the smallest asperity-covered surfaces.